The purpose of the present investigation is to examine the heart rates of three groups of stutterers during fluent and stuttered speech. By examining heart rates in stutterers, we are attempting to identify an objective method of measuring stutterers; emotional reactions during stuttering and suggesting that these emotional reactions may be one at-risk factor for continued stuttering development when considered in conjunction with a stutterer's speech abilities and communicative environment. Three groups of stutterers representing children close to the onset of stuttering, children who have stuttered for one to five years, and adult stutterers will be included. These 30 subjects will converse with the examiner while thy are videotape-recorded and their raw pulse signals are simultaneously recorded. Ten stuttered words and ten fluent words will be randomly selected for analysis. Analysis will involve locating the exact beginning and end of each stuttering or fluent word, determining a four-second time window around each target, digitizing and measuring the interbeat interval (IBI) in ms. associated with each of the targets, and storing the information in a data file for statistical analysis. The short- term goal of this investigation is to determine whether heart rates can be used as a method of determining a stutterer's physiological/emotional reactions during stuttering as well as a method of differentiating among stutterers. Information from the present investigation will help in the design of a larger study focusing on the relationship between heart rate measures during stuttering, behavioral responses during stuttering (facial actions) and stutterers' cognitive/perceptual awareness of stuttering. The ultimate goal of this research is a clinically useful diagnostic measure for quantifying emotional responses during stuttering and developing prognostic scale based upon these responses.